Sunlight backflow detection device, head-up display device and sunlight backflow detection method

Abstract

The invention relates to a sunlight backflow detection device, a head-up display device and a sunlight backflow detection method. In one aspect, a sunlight backward flow detection device is provided, which is arranged on a light emitting side of a display panel of an image generation unit of a head-up display device in use and outside a light envelope of the display panel, the sunlight backward flow detection device comprises: an imaging element for receiving light from the display panel to form an image; the image sensor is arranged on the light emitting side of the imaging element and used for capturing the image; and a monitoring device configured to detect sunlight backflow according to the captured image. Therefore, not only can the accuracy of sunlight backflow detection be improved, but also the internal structure of the head-up display device can be simplified.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular, to a sunlight backflow detection device, a head-up display device, and a sunlight backflow detection method. Background Art

[0002] Head Up Display (HUD) devices are widely used in vehicles and other transportation vehicles. They are used to display information such as vehicle conditions on the windshield of the vehicle, etc., so that the driver can obtain this information while maintaining continuous attention to road conditions.

[0003] Due to the light transmittance of the windshield, external sunlight will enter the HUD device through the windshield, and will reach and enter the display panel of the picture generation unit (PGU) along the reverse path of the display light of the HUD device. This phenomenon is usually called sunlight backflow. The energy of the sunlight backflowing into the display panel will be absorbed by the display panel and thus the temperature of the display panel will rise rapidly, which may cause damage to the display panel.

[0004] At present, sunlight backflow is detected by using a temperature sensor to detect the temperature of the PGU. However, usually, the temperature sensor is set far away from the display panel of the PGU, resulting in the measured temperature not accurately reflecting the actual temperature of the display panel, thus affecting the detection result. On the other hand, if the temperature sensor is directly set on the display panel, an additional connection structure is required, which will not only complicate the internal structure of the HUD device, but may also interfere with the display light emitted from the display panel. Summary of the invention

[0005] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0006] An object of the present disclosure is to provide a sunlight backflow detection device that can accurately detect sunlight backflow.

[0007] Another object of the present disclosure is to provide a sunlight backflow detection device that can simplify the internal structure of a HUD device.

[0008] In order to achieve the above object, according to one aspect of the present disclosure, a sunlight backflow detection device is provided, which is arranged on the light emitting side of the display panel of the PGU of the HUD device and outside the light envelope of the display panel during use. The sunlight backflow detection device includes:

[0009] An imaging element, for receiving light from the display panel to form an image;

[0010] an image sensor, arranged on the light-emitting side of the imaging element, for capturing the image; and

[0011] A monitoring device is configured to detect sunlight backflow based on the captured image.

[0012] In some embodiments, the imaging element may be a pinhole or an imaging lens.

[0013] In some embodiments, the image sensor may be an area array sensor or a line array sensor.

[0014] In some embodiments, the angle between the main light detection direction of the sunlight backflow detection device and the normal direction of the display panel may be in the range of 0 to 85°.

[0015] In some embodiments, the monitoring device may be configured to detect whether sunlight backflow occurs in the HUD device by comparing the grayscale value of one area among multiple areas constituting the captured image with the grayscale value of another area adjacent to the one area.

[0016] In some embodiments, the monitoring device may be configured to obtain the plurality of areas by compressing the captured images.

[0017] In some embodiments, the monitoring device may be configured to pre-process the captured image to reduce the grayscale value of the displayed content therein before detecting sunlight backflow based on the captured image.

[0018] In some embodiments, the monitoring device may be configured to determine the intensity of sunlight irradiating the display panel based on the maximum and minimum values ​​of the grayscale values ​​of the multiple regions when sunlight backflow is detected in the HUD device.

[0019] In some embodiments, the monitoring device may be configured to output a protection strategy according to the intensity of sunlight and the duration of sunlight shining on the display panel.

[0020] In some embodiments, the monitoring device may be configured to determine the intensity of sunlight irradiated on the display panel based on the maximum and minimum values ​​of the grayscale values ​​of the plurality of regions constituting the captured image.

[0021] According to another aspect of the present disclosure, a HUD device is further provided, which includes the sunlight backflow detection device according to any of the above embodiments.

[0022] According to another aspect of the present disclosure, a method for detecting sunlight backflow is provided, which includes:

[0023] On a light-emitting side of a display panel of a PGU of the HUD device and outside a light envelope of the display panel, receiving light from the display panel to form an image and capturing the image; and

[0024] Sunlight backflow is detected based on the captured image.

[0025] According to the above technical solution, by detecting the light spot on the surface of the display panel to detect sunlight backflow, it is possible to directly reflect whether there is sunlight backflow on the display panel and to directly display the state of sunlight backflowing to the display panel, so that a more accurate detection result can be obtained. In addition, by arranging the sunlight backflow detection device on the light-emitting side of the display panel, the complexity of the internal structure of the HUD device can be simplified. Moreover, by arranging the sunlight backflow detection device outside the light envelope of the display panel, it is possible to avoid interference with the display light emitted from the display panel, and thus avoid affecting the integrity of the displayed image. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The features and advantages of the embodiments of the present disclosure will become more easily understood through the following description with reference to the accompanying drawings. The drawings are not drawn to scale and some features may be exaggerated or reduced to show details of particular components.

[0027] In the attached picture:

[0028] Figure 1 A schematic diagram showing the backflow of external sunlight into the PGU of a HUD device in the related art.

[0029] Figure 2 It is a schematic diagram showing that the backflowing sunlight is focused on the light-incoming side of the display panel.

[0030] Figure 3 It is a schematic diagram showing the scattering of backflowing sunlight through the display panel.

[0031] Figure 4 It is a schematic diagram showing a sunlight backflow detection device according to an embodiment of the present disclosure in use.

[0032] Figure 5 FIG. 1 is a schematic diagram showing the light envelope of a display panel.

[0033] Figure 6 A schematic diagram of an exemplary image captured by an image sensor.

[0034] Figure 7 A schematic diagram of another exemplary image captured by an image sensor.

[0035] Figure 8 This is the spot diagram obtained when imaging using a pinhole.

[0036] Fig. 9 The figure is a schematic diagram showing the detection areas of the area array sensor and the line array sensor.

[0037] Fig.10 It is a schematic diagram showing the angle between the main light detection direction of the sunlight backflow detection device and the normal line of the display panel.

[0038] Fig.11 A schematic diagram of yet another exemplary image captured by an image sensor.

[0039] Fig.12 To make the reflector flip Figure 7 Schematic diagram of the image after the backflow spot moves.

[0040] Fig.13 It is a schematic structural diagram of a HUD device according to an embodiment of the present disclosure.

[0041] Fig.14 The present invention is a flow chart of a method for detecting sunlight backflow according to the present invention.

[0042] In the drawings, the same or corresponding technical features or components are represented by the same or corresponding reference numerals. DETAILED DESCRIPTION

[0043] The present disclosure is described in detail below with reference to the accompanying drawings by means of exemplary embodiments. It should be noted that the following detailed description of the present disclosure is only for illustrative purposes and is by no means a limitation of the present disclosure.

[0044] It should be noted that, for the sake of clarity, not all features of a specific implementation are described and illustrated in the specification and drawings. Furthermore, in order to avoid unnecessary details that obscure the technical solution that the present disclosure focuses on, only the device structure closely related to the technical solution of the present disclosure is described and illustrated in the specification and drawings, while other details that are not closely related to the technical content of the present disclosure and are known to those skilled in the art are omitted.

[0045] Reference Figure 1 In the related art, the HUD device 1' generally includes a PGU 10' (schematically shown in a dotted frame), a first reflector 20' and a second reflector 30'. The PGU 10' emits a display light S' carrying information such as vehicle conditions toward the first reflector 20', and the display light S' is reflected by the first reflector 20' to the second reflector 30', and then reflected by the second reflector 30' to the windshield 2', and finally reflected by the windshield 2' to the eye box 3', thereby, on the outside of the windshield 2' (i.e., Figure 1The eye box 3' refers to the range within which the eyes of a user (e.g., a driver) can move in a certain space while keeping the image clear and complete.

[0046] As mentioned above, due to the light transmittance of the windshield 2', the external sunlight 5' will enter the HUD device 1' through the windshield 2' and will basically follow the reverse path of the outgoing path of the display light S' ( Figure 1 The liquid (shown as a dotted line in FIG. 1 ) propagates (also called backflow) to PGU10' and enters PGU10'. Figure 1 As shown in FIG, PGU 10' includes a display panel 11' and a backlight device 12' for providing backlight to the display panel 11'. In the case of the above-mentioned sunlight backflow, the display panel 11' of PGU 10' will heat up rapidly due to the radiant heat brought by the sunlight backflowing thereon, and thus may be thermally damaged.

[0047] Although sunlight backflow is currently detected by detecting the temperature of PGU10' using a temperature sensor, the detection result is not accurate. This is because the temperature sensor is often set away from the display panel 11' of PGU10'. For example, the temperature sensor is often set near the exit surface 1'a of the HUD device 1', resulting in the measured temperature being unable to accurately reflect the temperature on the display panel 11' of PGU10', thereby affecting the accuracy of the detection result of sunlight backflow obtained based on the measured temperature. However, if the temperature sensor is directly set on the display panel 11', although the temperature of the display panel 11' can be detected, it is often necessary to set an additional connection structure for making the temperature sensor close to the display panel. The connection structure will occupy the internal space of the HUD device 1' to a certain extent, which will not only make the internal structure of the HUD device 1' complicated and affect the flexibility of the design, but may also interfere with the display light S' emitted from the display panel 11', affecting the quality of the displayed image.

[0048] This problem can be solved by the sunlight backflow detection device according to the embodiment of the present disclosure. Figures 2 to 7 A sunlight backflow detection device 10 according to an embodiment of the present disclosure will be described.

[0049] First, refer to Figure 2 and Figure 3 In the case of sunlight backflow, the external sunlight 5 will enter the HUD device 1 through the windshield 2, and the sunlight light L backflowing into the HUD device 1 will pass through the imaging magnifier group (for example, Figure 3The light is reflected by the first reflector 30 and the second reflector 40 of the HUD device 1 shown in FIG. 1 and focused on the light-incoming side 200a of the display panel 200 of the PGU 20, for example, focused on Figure 2 Thus, when sunlight backflow occurs, a light spot covering a portion of the surface of the display panel 200 located on the light exiting side 200 b is formed.

[0050] The sunlight light L irradiated on the display panel 200 is absorbed by the display panel 200, transmitted through the display panel 200, and scattered by the display panel 200. The surface of the display panel 200 is a non-polished surface, and scattering of the surface exists. Therefore, there is Figure 3 Based on this, the present disclosure attempts to obtain an image of a light spot on the display panel 200 by receiving the scattered light L1, and thereby realize the detection of sunlight backflow. This is described in detail below.

[0051] Reference Figures 4 to 7 According to an embodiment of the present disclosure, the sunlight backflow detection device 10 is arranged on the light emitting side 200b of the display panel 200 of the PGU 20 of the HUD device 1 during use, and outside the light envelope of the display panel 200 to perform detection toward the display panel 200 .

[0052] The PGU 20 includes a display panel 200 and a backlight device 201. The display panel 200 is used to allow light provided by the backlight device 201 to pass through it to form display light carrying information such as vehicle conditions, and it can be, for example, a liquid crystal display (LCD), a diffusion screen, etc. The backlight device 201 is arranged on the light-incoming side 200a of the display panel 200 to provide backlight to the display panel 200.

[0053] Here, the light-entering side 200a of the display panel 200 refers to the light-entering side of the display panel 200 with respect to the display light S. In other words, the light-entering side 200a is the side of the display panel 200 that is inside the PGU20, i.e., the inner side. The light-exiting side 200b of the display panel 200 is opposite to the light-entering side 200a, and refers to the side from which the display light S exits, that is, the side of the display panel 200 that is outside the PGU20, i.e., the outer side.

[0054] The light envelope of the display panel 200 refers to the boundary or outline of the space occupied by the light emitted from the display panel 200. Alternatively, the light envelope can also be understood as the boundary defined by the light emitted from the boundary portion of the display panel 200 in the process of propagating to the eye box. Figure 5As shown in , the light rays S1 and S2 emitted from the boundary portion of the display panel 200 define the boundary of the space C when propagating to the eye box range, wherein the space C is the space occupied by the emitted light, and the above boundary is the light envelope of the display panel 200. Therefore, by arranging the sunlight backflow detection device 10 outside the light envelope of the display panel 200, the sunlight backflow detection device 10 can be made not to affect the display light emitted from the display panel 200, thereby not affecting the integrity of the displayed image.

[0055] like Figure 4 As shown in FIG. 1 , a sunlight backflow detection device 10 (shown in a dotted frame) includes an imaging element 100 , an image sensor 101 and a monitoring device (not shown).

[0056] The imaging element 100 is used to receive light from the display panel 200 to form an image. Since the sunlight backflow detection device 10 is arranged outside the light envelope of the display panel 200, the light from the display panel 200 received by the imaging element 100 is the scattered light L1. Therefore, the image formed based on the scattered light L1 is an image of the surface 2001 of the display panel 200 located on the light exit side 200b of the display PGU 20.

[0057] The image sensor 101 is arranged on the light-exiting side of the imaging element 100 to capture the image formed by the imaging element 100. The light-exiting side is the light-exiting side with respect to the scattered light L1 received by the imaging element 100.

[0058] The monitoring device is configured to detect sunlight backflow based on the image captured by the image sensor 101. The captured image can show the surface 2001 of the display panel 200. For example, see Figure 6 and Figure 7 When sunlight backflow occurs, a light spot formed by the backflowing sunlight exists on the surface 2001, so the captured image 1020 can show the light spot B. Therefore, the captured image 1020 can be used to determine whether sunlight backflow occurs in the HUD device 1 by determining whether the light spot B exists on the image 1020, and it can be determined whether there is a risk of sunlight backflow damaging the display panel based on the state of the light spot B, such as brightness, so as to achieve the detection of sunlight backflow.

[0059] In the above embodiment, by detecting the light spot on the surface 2001 of the display panel 200 to detect sunlight backflow, it is possible to directly reflect whether there is sunlight backflow on the display panel 200 and to directly display the state of sunlight backflowing to the display panel 200, so that a more accurate detection result can be obtained. In addition, by arranging the sunlight backflow detection device 10 on the light-emitting side 200b of the display panel 200 instead of being in close contact with the display panel 200, the complexity of the internal structure of the HUD device 1 can be simplified. Moreover, by arranging the sunlight backflow detection device 10 outside the light envelope of the display panel 200, it is possible to avoid interference with the display light S emitted from the display panel 200, and thus avoid affecting the integrity of the displayed image.

[0060] In some embodiments, Figure 4 and Fig.10 As shown in , the imaging element 100 may be a pinhole.

[0061] The pinhole can perform pinhole imaging and has a simple structure. Therefore, the sunlight backflow detection device 10 can have a simpler structure, thereby further reducing the complexity of the internal structure of the HUD device 1.

[0062] The diameter of the pinhole can be, for example, 0.2 mm to 5 mm. When the diameter of the pinhole is less than 0.2 mm, too little light will pass through the pinhole for imaging, which will not only make the image too dim, but also may cause diffraction effect, affecting the imaging effect; and when the diameter of the pinhole is greater than 5 mm, the light passing through the pinhole will be defocused, which will make the image blurred, also affecting the imaging effect.

[0063] Below, an example of imaging using a pinhole is provided. In this example, the distance between the display panel 200 and the pinhole 100 is 50 mm, the diameter of the pinhole 100 is 0.2 mm, and the distance between the image sensor 101 and the pinhole 100 is 5 mm. Figure 8 , shows the point diagram sampled at three different positions of the image on the image sensor 101 obtained according to the imaging simulation under the above conditions, where: Figure 8 The spot diagram in (a) is sampled at the center of the image, the spot diagram in (b) is sampled at a distance of 15 mm from the center of the image, and the spot diagram in (c) is sampled at a distance of 30 mm from the center of the image. The radius of the spot in these spot diagrams is about 0.083 mm, which is less than the diffraction limit, so a clear image can be formed.

[0064] Optionally, the imaging element 100 may also be an imaging lens, or may be any other suitable type of imaging element.

[0065] In some embodiments, the image sensor 101 may be an array sensor. The array sensor may capture an image of the entire scene at once. Fig. 9 The area array sensor can capture the image of the entire surface 2001 of the display panel 200 at one time. That is to say, the detection area 1011 of the area array sensor is the entire surface 2001 of the display panel 200. Therefore, the sunlight backflow on the entire surface 2001 can be detected.

[0066] Optionally, the imaging element 100 may also be a linear array sensor. A linear array sensor can capture an image in one dimension. Fig. 9 The linear array sensor can capture the image of a line on the surface 2001 of the display panel 200 that passes through the surface 2001. That is, the detection area 1012 of the linear array sensor is a line on the surface 2001 of the display panel 200, and therefore, the backflow of sunlight on the line can be detected.

[0067] Exemplarily, the detection area of ​​the image sensor 101 may cover the entire surface 2001 of the display panel 200 , so as to be able to detect a light spot formed on any area of ​​the surface 2001 , thereby improving the accuracy of sunlight backflow detection.

[0068] In some embodiments, reference Fig.10 The sunlight backflow detection device 10 faces the display panel 200 , and the angle β between the main light detection direction M1 and the normal direction M2 of the display panel 200 can be in the range of 0 to 85°.

[0069] According to the surface scattering characteristics, as the angle β increases, the intensity of the scattered light will become smaller and smaller, making the energy received by the image sensor 101 smaller and smaller. When the angle β is greater than 85°, the intensity of the scattered light will be too small, making the energy received by the image sensor 101 too small, affecting the quality of the captured image, and thus affecting the accuracy of the sunlight backflow detection.

[0070] Next, the detection method of sunlight backflow is further explained.

[0071] In some embodiments, reference Figure 6 The monitoring device can be configured to detect whether sunlight backflow occurs in the HUD device 1 by comparing the grayscale value of one area among multiple areas constituting the captured image 1020 with the grayscale value of another area adjacent to the one area.

[0072] In the case of sunlight backflow, a light spot will appear on the surface 2001 of the display panel 200. The brightness of the light spot is usually greater than the brightness of other areas of the surface 2001 except the light spot. Therefore, the gray value of the light spot B on the image 1020 captured by the image sensor 101 will be greater than the gray value of the background, so that there will be an obvious light-dark boundary on the image 1020. Based on this, by comparing the gray value of one area among the multiple areas constituting the image 1020 with the gray value of another area adjacent to the one area, it is possible to detect whether the light-dark boundary exists on the image 1020, and thereby determine whether sunlight backflow occurs in the HUD device 1.

[0073] Exemplarily, whether sunlight backflow occurs can be detected based on the ratio of the grayscale value of the one region to the grayscale value of the other region. For example, when the ratio is greater than or equal to a first threshold (the one region is the light spot region of the image 1020, and the other region is the background region of the image 1020), or when the ratio is less than or equal to a second threshold (the one region is the background region of the image 1020, and the other region is the light spot region of the image 1020), it is determined that sunlight backflow occurs.

[0074] Optionally, whether sunlight backflow occurs may also be detected based on the difference between the grayscale value of the one region and the grayscale value of the other region. For example, when the absolute value of the difference is greater than or equal to a threshold, sunlight backflow is determined to exist. The multiple regions may be pixels of the captured image, or may be multiple regions obtained by compressing the captured image.

[0075] In some embodiments, the monitoring device may be configured to obtain the plurality of regions by compressing the captured images. In this way, the amount of data processing may be reduced, thereby improving the efficiency of detecting and responding to sunlight backflow.

[0076] Reference Fig.11 , the image 1020 captured by the image sensor 101 includes display content (Jinye 1st Road) 1021 and light spot B. The grayscale value of the display content 1021 is greater than the grayscale value of the background 1022, and less than the grayscale value of the light spot B. In this case, when sunlight backflow is detected based on the grayscale value, inaccurate detection may occur. For example, when one of the above-mentioned areas is a light spot area, and the above-mentioned other area is a display content area, the ratio of the grayscale value of the above-mentioned one area to the grayscale value of the above-mentioned other area may be less than the first threshold value, thereby making a determination that no sunlight backflow occurs, resulting in a detection error.

[0077] In this regard, in some embodiments, the monitoring device may be configured to pre-process the captured image 1020 to reduce the grayscale value of the displayed content 1021 therein before detecting sunlight backflow based on the captured image 1020 .

[0078] In this way, the difference between the grayscale value of the display content and the grayscale value of the light spot can be increased, thereby reducing the influence of the display content on the sunlight backflow detection, thereby improving the accuracy of the sunlight backflow detection.

[0079] Exemplarily, the displayed content may be blurred and smoothed by compressing the captured image, thereby reducing the grayscale value of the displayed content, or the grayscale value of the displayed content may be reduced by removing the displayed content and filling the removed portion with the grayscale of the background pixels through image processing.

[0080] Alternatively, in some embodiments, the display content light entering the image sensor can be filtered according to the difference between the backflowing sunlight and the display content light, thereby reducing the impact of the display content on the image sensor. In other words, the monitoring device can be configured to filter the display content light entering the image sensor according to the difference between the backflowing sunlight and the display content light.

[0081] For example, since the polarization direction and wavelength of the light that the image sensor can sense are different from the characteristics of the display content light, the above filtering can be performed based on the differences in polarization and wavelength bands. Specifically, the liquid crystal display panel emits polarized light in a first direction, while the polarization direction of the light entering the image sensor is a second polarization direction. The first direction is not parallel or perpendicular to the second direction, so the display content light does not enter or only a small part enters the image sensor, thereby filtering the display content light entering the image sensor.

[0082] In some embodiments, the monitoring device may be configured to determine the intensity of sunlight irradiated on the display panel 200 based on the maximum and minimum values ​​of the grayscale values ​​of the multiple regions when sunlight backflow is detected in the HUD device 1 .

[0083] As mentioned before, there is a corresponding relationship between the brightness of the light spot on the surface 2001 of the display panel 200 and the grayscale of the light spot B on the image 1020 captured by the image sensor 101, and therefore, the corresponding light intensity can be obtained according to the grayscale sensed by the image sensor 101. In the case of sunlight backflow, the maximum value of the grayscale value of the image 1020 corresponds to the light intensity at the light spot on the surface 2001 of the display panel 200, and the minimum value corresponds to the light intensity at other areas of the surface 2001 except the light spot, and therefore, according to the difference between the maximum value and the minimum value, the intensity of the sunlight irradiated on the surface 2001 of the display panel 200 can be obtained.

[0084] Optionally, the intensity of the sunlight can be determined directly without using the grayscale value to determine whether sunlight backflow occurs. In this case, the monitoring device can be configured to determine the intensity of the sunlight irradiated on the display panel based on the maximum and minimum values ​​of the grayscale values ​​of the multiple regions constituting the captured image.

[0085] It is understandable that this method can also be used to determine whether sunlight backflow occurs. For example, when the difference between the maximum value and the minimum value is greater than or equal to a threshold, sunlight backflow is determined to occur. The threshold can be determined by calibration or empirical value.

[0086] Optionally, the background is often dark, so the influence of the minimum value can be ignored. Therefore, it can be judged whether there is sunlight backflow according to the above maximum value. Specifically, when the maximum value is greater than or equal to a threshold, it is determined that there is sunlight backflow.

[0087] In some embodiments, the monitoring device may be configured to output a protection strategy according to the intensity of the sunlight and the duration of the sunlight irradiating the display panel 200 .

[0088] For example, when the intensity is greater than or equal to a threshold, the timing starts, and when the duration is greater than the set target time, the sunlight backflow protection strategy is output. It is also conceivable that when the product of the intensity and the duration is greater than the set target value, the sunlight backflow protection strategy is output.

[0089] The sunlight backflow protection strategy may be, for example, reducing the display brightness of the HUD device 1 to reduce the amount of light from the backlight reaching the display panel 200, or starting a fan to cool the display panel 200, or rotating the reflector and shutting down temporarily to prevent sunlight from backflowing to the display panel 200, etc. Figure 7 and Fig.12 , by rotating the reflector, the position of the light spot B moves, for example, from Figure 7 Move the position shown in Fig.12 As a result, the area of ​​the light spot B on the display panel 200 is reduced, thereby reducing the risk of sunlight backflow.

[0090] In some examples, the monitoring device has a communication function and can access a wired network or a wireless network. In some examples, the monitoring device can receive data based on the wired network or the wireless network accessed. It can be understood that the monitoring device undertakes the calculation and processing work of the technical solution of the present disclosure, and the present disclosure does not limit this.

[0091] In some examples, the monitoring device has a communication function, accesses a wired or wireless network, obtains the temperature, time, and sunshine conditions of the vehicle's location, and outputs a sunlight backflow protection strategy based on whether there is sunlight backflow.

[0092] The monitoring device of the present disclosure may include one or more of the following components: a processor and a memory. Optionally, the processor uses various interfaces and lines to connect the various parts of the entire monitoring device, and executes various functions and processes data of the monitoring device by running or executing instructions, programs, code sets or instruction sets stored in the memory, and calling data stored in the memory. Optionally, the processor can be implemented in at least one hardware form of digital signal processing (DSP), field programmable gate array (FPGA), and programmable logic array (PLA). The processor can integrate one or more combinations of a central processing unit (CPU), a graphics processing unit (GPU), a neural network processor (NPU), and a baseband chip. Among them, the CPU mainly processes the operating system, UI, and application programs, etc., the GPU is responsible for rendering and drawing the content required to be displayed on the touch display, the NPU is used to implement artificial intelligence (AI) functions, and the baseband chip is used to process wireless communications. It is understandable that the above-mentioned baseband chip may not be integrated into the processor, but may be implemented by a separate chip.

[0093] The memory may include a random access memory (RAM) or a read-only memory (ROM). Optionally, the memory includes a non-transitory computer-readable storage medium. The memory may be used to store instructions, programs, codes, code sets, or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above various method embodiments, etc., and the data storage area may store data created according to the use of the monitoring device, etc.

[0094] In addition, those skilled in the art will appreciate that the monitoring device may include more or fewer components than those described above, or may combine certain components, or may have different component arrangements. For example, the monitoring device may also include a display screen, a camera assembly, a radio frequency circuit, an input unit, a sensor, an audio circuit, a WiFi module, a power supply, a Bluetooth module, and other components, which will not be described in detail herein.

[0095] According to another aspect of the present disclosure, Fig.13 As shown in , a HUD device 1 is also provided, which includes the above-mentioned sunlight backflow detection device 10.

[0096] In addition, the HUD device 1 may also include an imaging magnifying glass group, which may include, for example, a first reflector 30 and a second reflector 40 . The display light S emitted by the PGU20 may be reflected by the second reflector 40 and the first reflector 30 in sequence and then emitted from the HUD device 1 .

[0097] According to another aspect of the present disclosure, Fig.14 As shown in , a method for detecting sunlight backflow is also provided. The method for detecting sunlight backflow includes:

[0098] On a light-emitting side of a display panel of a PGU of the HUD device and outside a light envelope of the display panel, receiving light from the display panel to form an image and capturing the image; and

[0099] Sunlight backflow is detected based on the captured image.

[0100] In some embodiments, detecting sunlight backflow based on the captured image may include:

[0101] Whether sunlight backflow occurs in the HUD device is detected by comparing the grayscale value of one area among a plurality of areas constituting the captured image with the grayscale value of another area adjacent to the one area.

[0102] In some implementations, the plurality of regions may be obtained by compressing the captured image.

[0103] In some embodiments, before detecting sunlight backflow based on the captured image, the captured image may be pre-processed to reduce the grayscale value of the displayed content therein.

[0104] In some implementations, when sunlight backflow is detected in the HUD device, the intensity of sunlight irradiated on the display panel may be determined based on the maximum and minimum values ​​of the grayscale values ​​of the multiple regions.

[0105] In the present disclosure, the terms "first", "second", etc. are used only for the purpose of convenience of description and should not be regarded as limiting. In addition, although the present disclosure has been described with reference to exemplary embodiments, it should be understood that the present disclosure is not limited to the specific embodiments described and shown in detail herein. Those skilled in the art may make various changes to the exemplary embodiments without departing from the scope defined by the claims of the present disclosure.

[0106] The features mentioned and / or shown in the above description of the exemplary embodiments of the present disclosure may be combined in the same or similar manner into one or more other embodiments, combined with the features in other embodiments or substituted for the corresponding features in other embodiments. The technical solutions obtained by these combinations or substitutions shall also be deemed to be included in the protection scope of the present disclosure.

Claims

1. A sunlight backflow detection device, characterized in that: The sunlight backflow detection device is arranged on the light exit side of the display panel of the image generation unit of the head-up display device and outside the light envelope of the display panel during use, and comprises: An imaging element, used for receiving light from the display panel to form an image; an image sensor, arranged on the light-emitting side of the imaging element, for capturing the image; and A monitoring device is configured to detect sunlight backflow based on the captured image.

2. The sunlight backflow detection device according to claim 1, characterized in that: The imaging element is a pinhole or an imaging lens.

3. The sunlight backflow detection device according to claim 1, characterized in that: The image sensor is an area array sensor or a line array sensor.

4. The sunlight backflow detection device according to claim 1, characterized in that: The angle between the main light detection direction of the sunlight backflow detection device and the normal direction of the display panel is in the range of 0 to 85 degrees.

5. The sunlight backflow detection device according to any one of claims 1 to 4, characterized in that: The monitoring device is configured to detect whether sunlight backflow occurs in the head-up display device by comparing a grayscale value of one area among a plurality of areas constituting the captured image with a grayscale value of another area adjacent to the one area.

6. The sunlight backflow detection device according to claim 5, characterized in that: The monitoring device is configured to obtain the plurality of areas by compressing the captured image.

7. The sunlight backflow detection device according to claim 5, characterized in that: The monitoring device is configured to pre-process the captured image to reduce the grayscale value of the displayed content therein before detecting sunlight backflow based on the captured image.

8. The sunlight backflow detection device according to claim 5, characterized in that: The monitoring device is configured to determine the intensity of sunlight irradiated on the display panel according to the maximum value and the minimum value of the grayscale values ​​of the multiple regions when sunlight backflow is detected in the head-up display device.

9. The sunlight backflow detection device according to claim 8, characterized in that: The monitoring device is configured to output a protection strategy according to the intensity of the sunlight and the duration of the sunlight irradiating the display panel.

10. The sunlight backflow detection device according to any one of claims 1 to 4, characterized in that: The monitoring device is configured to determine the intensity of sunlight irradiated on the display panel based on the maximum value and the minimum value among the grayscale values ​​of multiple areas constituting the captured image.

11. A head-up display device, characterized in that: It comprises the sunlight backflow detection device according to any one of claims 1 to 10.

12. A method for detecting sunlight backflow, characterized in that: include: At a light exiting side of a display panel of an image generating unit of a head-up display device and outside a light envelope of the display panel, receiving light from the display panel to form an image and capturing the image; as well as Sunlight backflow is detected based on the captured image.

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